Let me start off by stating that LowRanger96 and I have already discussed this, and we're both stumped.
Now then, I have a 1990 Ranger being run by an FLH2 ECM with a Quarterhorse attached, and for whatever reason, neither of us know or can tell why it's not switching to open loop. I replaced the junkyard O2 sensor I had with a new Bosch sensor as well. His BE2012 also shows different values than my own, which further adds to the confusion. Attached isthe database I'm using. Logs will follow shortly.